JP6853269B2 - High pressure fuel supply pump with electromagnetic intake valve - Google Patents

Description

The present invention relates to a high-pressure fuel supply pump that supplies high-pressure fuel to a fuel injection valve that injects fuel directly into a cylinder of an internal combustion engine, and particularly provides a high-pressure fuel supply provided with an electromagnetic suction valve that adjusts the amount of discharged fuel. Regarding the pump.

In the high-pressure fuel supply pump provided with the conventional electromagnetic suction valve described in Patent Document 1 and Patent Document 2 below, the suction valve is held in the valve opening direction by the urging force of the spring when the electromagnetic coil is not energized. The electromagnetic suction valve that is used is described. When the electromagnetic coil is energized, the suction valve closes due to the magnetic attraction generated in the electromagnetic suction valve. Therefore, the opening / closing motion of the intake valve can be controlled by the presence / absence of energization of the electromagnetic coil, and thereby the supply amount of high-pressure fuel can be controlled.

Further, the conventional electromagnetic suction valve described in Patent Document 1 guides a flat suction valve, a seat member that seats the suction valve, a rod that holds the suction valve in the valve opening direction by the urging force of a spring, and a rod. It is described that it is composed of the members to be used. By guiding the rod in this way, the operation of the suction valve can be stabilized and accurate flow rate control can be performed.

Further, in the conventional electromagnetic suction valve described in Japanese Patent Application Laid-Open No. 2012-251447, a cup-type suction valve, a seat member having both functions of a seat and a rod guide of the suction valve, and a spring urging force are used. It is stated that it is composed of a rod that holds the suction valve in the valve opening direction. Even in such a configuration, it is possible to stabilize the operation of the suction valve and perform accurate flow rate control.

Japanese Unexamined Patent Publication No. 2016-094913 Japanese Unexamined Patent Publication No. 2012-251447

However, in the electromagnetic suction valve of the conventional high-pressure fuel supply pump described in Patent Documents 1 and 2 described above, the suction valve seat portion and the rod guide portion are composed of separate parts. Further, in Patent Document 2, the suction valve seat portion and the rod collision surface are formed of different planes. In this case, the inclination when the suction valve and the rod collide becomes large. When the suction valve and the rod collide with each other in an inclined state, the rods collide with each other in a corner contact state, so that there is a problem that stress concentration occurs and wear occurs.

An object of the present invention is to prevent wear at a rod collision portion by reducing the inclination of the suction valve and the rod in the electromagnetic suction valve of the high-pressure fuel supply pump.

In order to achieve the above object, the high-pressure fuel supply pump of the present invention has a suction valve having a flat surface portion, a rod portion that collides with the flat surface portion and urges the suction valve in the valve opening direction, and is parallel to the flat surface portion. A seat member having a surface and having a suction valve seat on which the flat surface portion of the suction valve is seated is provided on a parallel surface, and the suction valve seat is on the same plane as the collision surface on which the rod portion of the flat surface portion collides. The seat member is provided with a fuel passage through which fuel flows from the low-pressure flow path, and a guide that guides the rod portion on the side opposite to the suction valve with respect to the contact position between the rod portion and the flat surface portion. The portion is integrally formed with the seat member, and the guide portion provided for the rod portion is provided at only one place and at a position not overlapping with the opening of the fuel passage, and the opening of the fuel passage is provided. The member provided at a position overlapping the portion is only the rod portion, and the thickness of the suction valve in the rod portion axial direction is thicker than the thickness of the portion of the seat member where the suction valve seat is provided in the rod portion axial direction.
To.

According to the present invention configured as described above, it is possible to reduce the inclination when the rod and the suction valve collide with each other, and it is possible to prevent the occurrence of wear at the rod collision portion.

It is a vertical sectional view of the high pressure fuel supply pump according to 1st Embodiment of this invention. It is a horizontal sectional view seen from above of the high pressure fuel supply pump by 1st Embodiment of this invention. FIG. 5 is a vertical cross-sectional view of the high-pressure fuel supply pump according to the first embodiment of the present invention as viewed from a different direction from FIG. It is an enlarged vertical sectional view of the electromagnetic suction valve mechanism of the high pressure fuel supply pump according to the 1st Embodiment of this invention, and shows the state which the electromagnetic suction valve mechanism is in a valve open state. The block diagram of the engine system to which the high pressure fuel supply pump according to 1st Example of this invention was applied is shown.

Hereinafter, the present invention will be described in detail based on the examples shown in the drawings.

First, the first embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 5 shows an overall configuration diagram of the engine system. The part surrounded by the broken line indicates the main body of the high-pressure fuel supply pump (hereinafter referred to as the high-pressure fuel supply pump), and the mechanism / parts shown in the broken line are integrally incorporated in the pump body 1. Is shown.

The fuel in the fuel tank 20 is pumped by the feed pump 21 based on a signal from the engine control unit 27 (hereinafter referred to as an ECU). This fuel is pressurized to an appropriate feed pressure and sent to the low pressure fuel suction port 10a of the high pressure fuel supply pump through the suction pipe 28.

The fuel that has passed through the suction joint 51 from the low-pressure fuel suction port 10a reaches the suction port 31b of the electromagnetic suction valve mechanism 300 that constitutes the capacity variable mechanism via the pressure pulsation reduction mechanism 9 and the suction passage 10b.

The fuel that has flowed into the electromagnetic suction valve mechanism 300 passes through the suction port that is opened and closed by the suction valve 30 and flows into the pressurizing chamber 11. The cam mechanism 93 of the engine gives the plunger 2 the power to reciprocate. Due to the reciprocating motion of the plunger 2, fuel is sucked from the suction valve 30 in the descending stroke of the plunger 2, and the fuel is pressurized in the ascending stroke. Fuel is pumped to the common rail 23 on which the pressure sensor 26 is mounted via the discharge valve mechanism 8. Then, the injector 24 injects fuel into the engine based on the signal from the ECU 27. This embodiment is a high-pressure fuel supply pump applied to a so-called direct injection engine system in which the injector 24 injects fuel directly into the cylinder cylinder of the engine.

The high-pressure fuel supply pump discharges a desired fuel flow rate of the supplied fuel by a signal from the ECU 27 to the electromagnetic suction valve mechanism 300.

FIG. 1 shows a vertical cross-sectional view of the high-pressure fuel supply pump of this embodiment, and FIG. 2 is a horizontal cross-sectional view of the high-pressure fuel supply pump as viewed from above. Further, FIG. 3 is a vertical cross-sectional view of the high-pressure fuel supply pump as viewed from a direction different from that of FIG. FIG. 4 is an enlarged view of 300 parts of the electromagnetic suction valve mechanism.

As shown in FIGS. 1 and 3, the high-pressure fuel supply pump of this embodiment is closely fixed to the high-pressure fuel supply pump mounting portion 90 of the internal combustion engine. Specifically, a screw hole 1b is formed in the mounting flange 1a provided on the pump body 1 of FIG. 2, and by inserting a plurality of bolts into the screw hole 1b, the mounting flange 1a becomes a high-pressure fuel supply pump for an internal combustion engine. It adheres to the mounting portion 90 and is fixed.

An O-ring 61 is fitted into the pump body 1 for sealing between the high pressure fuel supply pump mounting portion 90 and the pump body 1 to prevent engine oil from leaking to the outside.

A cylinder 6 that guides the reciprocating motion of the plunger 2 and forms a pressurizing chamber 11 together with the pump body 1 is attached to the pump body 1. That is, the plunger 2 reciprocates inside the cylinder to change the volume of the pressurizing chamber. Further, an electromagnetic suction valve mechanism 300 for supplying fuel to the pressurizing chamber 11 and a discharge valve mechanism 8 for discharging fuel from the pressurizing chamber 11 into the discharge passage are provided.

The cylinder 6 is press-fitted with the pump body 1 on the outer peripheral side thereof, and at the fixed portion 6a, the body is deformed to the inner peripheral side to press the cylinder upward in the drawing, and the upper end surface of the cylinder 6 enters the pressurizing chamber 11. The pressurized fuel is sealed so that it does not leak to the low pressure side.

At the lower end of the plunger 2, a tappet 92 is provided that converts the rotational motion of the cam 93 attached to the camshaft of the internal combustion engine into a vertical motion and transmits it to the plunger 2. The plunger 2 is crimped to the tappet 92 by a spring 4 via a retainer 15. As a result, the plunger 2 can be reciprocated up and down with the rotational movement of the cam 93.

Further, the plunger seal 13 held at the lower end of the inner circumference of the seal holder 7 is installed in a slidable contact with the outer periphery of the plunger 2 at the lower portion in the drawing of the cylinder 6. As a result, when the plunger 2 slides, the fuel in the sub chamber 7a is sealed and prevented from flowing into the internal combustion engine. At the same time, it prevents the lubricating oil (including the engine oil) that lubricates the sliding portion in the internal combustion engine from flowing into the pump body 1.

As shown in FIGS. 2 and 3, a suction joint 51 is attached to the side surface of the pump body 1 of the high-pressure fuel supply pump. The suction joint 51 is connected to a low-pressure pipe that supplies fuel from the fuel tank 20 of the vehicle, from which fuel is supplied to the inside of the high-pressure fuel supply pump. The suction filter 52 has a role of preventing foreign matter existing between the fuel tank 20 and the low-pressure fuel suction port 10a from being absorbed into the high-pressure fuel supply pump by the flow of fuel.

The fuel that has passed through the low-pressure fuel suction port 10a goes to the pressure pulsation reduction mechanism 9 through the low-pressure fuel suction port 10b that communicates vertically with the pump body 1 shown in FIG. The pressure pulsation reducing mechanism 9 is arranged between the damper cover 14 and the upper end surface of the pump body 1, and is supported from below by the holding member 9a arranged on the upper end surface of the pump body 1. Specifically, the pressure pulsation reduction mechanism 9 is configured by superimposing two diaphragms, gas is sealed in the inside thereof at 0.3 MPa to 0.6 MPa, and the outer peripheral edge portion is fixed by welding. Therefore, the outer peripheral edge portion is thin and is configured to become thicker toward the inner peripheral side.

Then, a convex portion for fixing the outer peripheral edge portion of the pressure pulsation reducing mechanism 9 from below is formed on the upper surface of the holding member 9a. On the other hand, a convex portion for fixing the outer peripheral edge portion of the pressure pulsation reducing mechanism 9 from above is formed on the lower surface of the damper cover 14. These convex portions are formed in a circular shape, and the pressure pulsation reduction mechanism 9 is fixed by being sandwiched by these convex portions. The damper cover 14 is press-fitted and fixed to the outer edge of the pump body 1, but at this time, the holding member 9a is elastically deformed to support the pressure pulsation reducing mechanism 9. In this way, a damper chamber 10c communicating with the low-pressure fuel suction ports 10a and 10b is formed on the upper and lower surfaces of the pressure pulsation reducing mechanism 9. Although not shown in the figure, the holding member 9a is formed with a passage connecting the upper side and the lower side of the pressure pulsation reducing mechanism 9, whereby the damper chamber 10c is formed on the upper and lower surfaces of the pressure pulsation reducing mechanism 9. Is formed in.

The fuel that has passed through the damper chamber 10c then reaches the suction port 31b of the electromagnetic suction valve mechanism 300 via the low-pressure fuel flow path 10d formed by communicating with the pump body in the vertical direction. The suction port 31b is formed so as to communicate with the suction valve seat member 31 forming the suction valve seat 31a in the vertical direction.

As shown in FIG. 2, the discharge valve mechanism 8 provided at the outlet of the pressurizing chamber 11 directs the discharge valve seat 8a, the discharge valve 8b that comes into contact with and separates from the discharge valve seat 8a, and the discharge valve 8b toward the discharge valve seat 8a. It is composed of a discharge valve spring 8c for urging and a discharge valve stopper 8d for determining a stroke (moving distance) of the discharge valve 8b. The discharge valve stopper 8d and the pump body 1 are joined by welding at the contact portion 8e to shield the fuel from the outside.

When there is no fuel differential pressure between the pressurizing chamber 11 and the discharge valve chamber 12a, the discharge valve 8b is crimped to the discharge valve seat 8a by the urging force of the discharge valve spring 8c to be in a closed state. Only when the fuel pressure in the pressurizing chamber 11 becomes higher than the fuel pressure in the discharge valve chamber 12a does the discharge valve 8b open against the discharge valve spring 8c. Then, the high-pressure fuel in the pressurizing chamber 11 is discharged to the common rail 23 through the discharge valve chamber 12a, the fuel discharge passage 12b, and the fuel discharge port 12. When the discharge valve 8b is opened, it comes into contact with the discharge valve stopper 8d and the stroke is limited. Therefore, the stroke of the discharge valve 8b is appropriately determined by the discharge valve stopper 8d. As a result, it is possible to prevent the fuel discharged at high pressure into the discharge valve chamber 12a from flowing back into the pressurizing chamber 11 due to the delay in closing the discharge valve 8b due to the stroke being too large, and the efficiency of the high pressure fuel supply pump can be prevented. The decrease can be suppressed. Further, when the discharge valve 8b repeats the valve opening and closing movements, the discharge valve 8b is guided by the outer peripheral surface of the discharge valve stopper 8d so that the discharge valve 8b moves only in the stroke direction. By doing so, the discharge valve mechanism 8 becomes a check valve that limits the fuel flow direction.

As described above, the pressurizing chamber 11 includes a pump housing 1, an electromagnetic suction valve mechanism 300, a plunger 2, a cylinder 6, and a discharge valve mechanism 8.

Here, the details of this embodiment will be described with reference to FIG. FIG. 4 is an enlarged view of the electromagnetic suction valve 300, which is a state in which the electromagnetic coil 43 is not energized and is in a non-energized state, and the pressure in the pressurizing chamber 11 is low (pressure fed by the feed pump 21). ..

When the plunger 2 moves in the direction of the cam 93 due to the rotation of the cam 93 and is in the suction process state, the volume of the pressurizing chamber 11 increases and the fuel pressure in the pressurizing chamber 11 decreases.

When the fuel pressure in the pressurizing chamber 11 becomes lower than the pressure of the suction port 31b in this stroke, the suction valve 30 is opened. 30a indicates the maximum opening degree, and at this time, the suction valve 30 comes into contact with the stopper 32. When the suction valve 30 opens, the opening 31c formed in the seat member 31 opens. The fuel passes through the opening 31c and flows into the pressurizing chamber 11 through the hole 1f formed in the pump body 1 in the lateral direction. The hole 1f also constitutes a part of the pressurizing chamber 11.

After the plunger 2 finishes the inhalation stroke, the plunger 2 shifts to the ascending movement and shifts to the ascending stroke. Here, the electromagnetic coil 43 remains in a non-energized state and no magnetic urging force acts on it. The rod urging spring 40 is set to urge the rod convex portion 35a which is convex on the outer diameter side of the rod 35 and to have a necessary and sufficient urging force to keep the suction valve 30 open in a non-energized state. There is. The volume of the pressurizing chamber 11 decreases with the ascending movement of the plunger 2. In this state, the fuel once sucked into the pressurizing chamber 11 is sucked again through the opening 30a of the suction valve 30 in the opened state. Since it is returned to the passage 10d, the pressure in the pressurizing chamber does not rise. This process is called the return process.

In this state, when a control signal from the engine control unit 27 (hereinafter referred to as an ECU) is applied to the electromagnetic suction valve mechanism 300, a current flows through the electromagnetic coil 43 via the terminal 46. A magnetic attraction force acts between the magnetic core 39 and the anchor 36, and the magnetic core 39 and the anchor 36 come into contact with each other on the magnetic attraction surface S. The magnetic attraction force overcomes the urging force of the rod urging spring 40 to urge the anchor 36, and the anchor 36 engages with the rod convex portion 35a to move the rod 35 away from the suction valve 30.

At this time, the suction valve 30 is closed by the urging force of the suction valve urging spring 33 and the fluid force caused by the fuel flowing into the suction passage 10d. After the valve is closed, the fuel pressure in the pressurizing chamber 11 rises with the ascending motion of the plunger 2, and when the pressure exceeds the pressure of the fuel discharge port 12, high-pressure fuel is discharged through the discharge valve mechanism 8 to the common rail 23. Be supplied. This process is called a discharge process.

That is, the ascending stroke from the lower start point to the upper start point of the plunger 2 consists of a return stroke and a discharge stroke. Then, by controlling the energization timing of the electromagnetic suction valve mechanism 300 to the coil 43, the amount of high-pressure fuel discharged can be controlled. If the timing of energizing the electromagnetic coil 43 is advanced, the ratio of the return stroke in the compression stroke is small and the ratio of the discharge stroke is large. That is, less fuel is returned to the suction passage 10d, and more fuel is discharged at high pressure. On the other hand, if the energization timing is delayed, the ratio of the return stroke is large and the ratio of the discharge stroke is small during the compression stroke. That is, more fuel is returned to the suction passage 10d, and less fuel is discharged at high pressure. The energization timing of the electromagnetic coil 43 is controlled by a command from the ECU 27.
With the above configuration, the amount of fuel discharged at high pressure can be controlled to the amount required by the internal combustion engine by controlling the energization timing of the electromagnetic coil 43.

The suction valve portion includes a suction valve 30, a suction valve seat 31, a suction valve stopper 32, and a suction valve urging spring 33. The suction valve seat 31 is cylindrical and has a seat portion 31a in the inner peripheral axial direction and one or more suction passage portions 31b radially around the cylindrical shaft, and is press-fitted into the pump body 1 on the outer peripheral cylindrical surface. Be retained.

The suction valve urging spring 33 is arranged on the inner peripheral side of the suction valve stopper 32 in a small diameter portion for partially stabilizing one end of the spring coaxially, and the suction valve 30 sucks with the suction valve seat portion 31a. The suction valve urging spring 33 is fitted to the valve guide portion 30b between the valve stoppers 32. The suction valve urging spring 33 is a compression coil spring, and is installed so that the urging force acts in the direction in which the suction valve 30 is pressed against the suction valve seat portion 31a. The spring is not limited to the compression coil spring, and may be in any form as long as it can obtain an urging force, and may be a leaf spring having an urging force integrated with the suction valve.

By configuring the suction valve portion in this way, in the suction step of the pump, the fuel that has passed through the suction passage 31b and entered the inside passes between the suction valve 30 and the seat portion 31a, and the outer periphery of the suction valve 30 is formed. It passes through the fuel passages in the gaps between the side and the suction valve stopper 32, passes through the passages of the pump body 1 and the cylinder, and allows fuel to flow into the pump chamber. Further, in the discharge process of the pump, the discharge valve 30 functions as a check valve to prevent backflow of fuel to the inlet side by contact-sealing the suction valve seat portion 31a.

The axial movement amount 30a of the suction valve 30 is finitely regulated by the suction valve stopper 32. This is because if the amount of movement is too large, the reverse flow rate increases due to the response delay when the suction valve 30 is closed, and the performance as a pump deteriorates. The regulation of the amount of movement can be defined by the axial shape and dimensions of the suction valve seat 31a, the suction valve 30, and the suction valve stopper 32, and the press-fitting position.

Since the suction valve 30, the suction valve seat 31a, and the suction valve stopper 32 repeatedly collide with each other when they operate, a material obtained by heat-treating martensitic stainless steel having high strength, high hardness, and excellent corrosion resistance is used. An austenitic stainless steel material is used for the suction valve spring 33 in consideration of corrosion resistance.

Next, the solenoid mechanism unit will be described. The solenoid mechanism portion includes a rod 35 which is a movable portion, an anchor 36, a rod guide 37 which is a fixed portion, a first core 38, a second core 39, a rod urging spring 40, and an anchor urging spring 41.

The rod 35 and the anchor 36, which are movable parts, are formed as separate members. The rod 35 is slidably held on the inner peripheral side of the rod guide 37 in the axial direction, and the inner peripheral side of the anchor 36 is slidably held on the outer peripheral side of the rod 35. That is, both the rod 35 and the anchor 36 are configured to be slidable in the axial direction within a range geometrically regulated.

Since the anchor 36 moves freely and smoothly in the axial direction in the fuel, the anchor 36 has one or more through holes 36a penetrating in the axial direction of the component, and the restriction of movement due to the pressure difference between the front and rear of the anchor is eliminated as much as possible. The rod guide 37 is inserted radially into the inner peripheral side of the hole into which the suction valve of the pump body 1 is inserted, is abutted against one end of the suction valve seat in the axial direction, and is welded to the pump body 1. It is configured to be arranged so as to be sandwiched between the fixed first core 38 and the pump main body 1.
Like the anchor 36, the rod guide 37 is also provided with a through hole 37a that penetrates in the axial direction so that the pressure in the fuel chamber on the anchor side does not hinder the movement of the anchor so that the anchor can move freely and smoothly. It is configured.

The first core 38 has a thin-walled cylindrical shape on the side opposite to the portion to be welded to the pump body, and the second core 39 is inserted and fixed by welding on the inner peripheral side thereof. A rod urging spring 40 is arranged on the inner peripheral side of the second core 39 with a small diameter portion as a guide, and the rod 35 comes into contact with the suction valve 30 and the suction valve is separated from the suction valve seat portion 31a, that is, Gives urging force in the valve opening direction of the suction valve.

The anchor urging spring 41 is arranged to give urging force to the anchor 36 in the direction of the rod brim portion 35a while maintaining coaxiality by inserting a direction end into a guide portion 37a having a cylindrical diameter provided on the center side of the rod guide 37. The movement amount 36e of the anchor 36 is set to be larger than the movement amount 30a of the suction valve 30. This is because the suction valve 30 is surely closed.

Since the rod 35 and the rod guide 37 slide on each other and the rod 35 repeatedly collides with the suction valve 30, martensitic stainless steel that has been heat-treated is used in consideration of hardness and corrosion resistance. Magnetic stainless steel is used for the anchor 36 and the second core 39 to form a magnetic circuit, and the collision surfaces of the anchor 36 and the second core are surface-treated to improve the hardness. In particular, it is hard Cr plating or the like, but this is not the case. Austenitic stainless steel is used for the rod urging spring 40 and the anchor urging spring 41 in consideration of corrosion resistance.

Three springs are configured in the suction valve portion and the solenoid mechanism portion. It is composed of a suction valve urging spring 33 formed of a suction valve portion, a rod urging spring formed of a solenoid mechanism portion, and an anchor urging spring. In this embodiment, coil springs are used for all the springs, but any spring can be configured as long as it can obtain an urging force.

The relationship between these three spring forces is composed of the following equation.
The urging force of the rod urging spring 40> the urging force of the anchor urging spring 41 + the urging force of the suction valve urging spring 33 + the force that the suction valve tries to close due to the fluid.
Due to this relationship, in the non-energized state, the force f1 acts on the rod 35 in the direction of pulling the suction valve 30 away from the suction valve seat portion 31a, that is, in the direction in which the valve opens, due to each spring force. From equation (1), f1 is as follows.
f1 = urging force of the rod urging spring 40- (the urging force of the anchor urging spring 41 + the urging force of the suction valve urging spring 33 + the force at which the suction valve is closed by the fluid) The configuration of the coil portion will be described. The coil portion includes a first yoke 42, an electromagnetic coil 43, a second yoke 44, a bobbin 45, a terminal 46, and a connector 47. A coil 43 in which a copper wire is wound a plurality of times on a bobbin 45 is arranged so as to be surrounded by a first yoke 42 and a second yoke, and is molded and fixed integrally with a connector which is a resin member. Each end of the two terminals 46 is connected to both ends of the copper wire of the coil so as to be energized. Similarly, the terminal 46 is also molded integrally with the connector so that the remaining end can be connected to the engine control unit side.

As for the coil portion, the hole portion at the center of the first yoke is press-fitted into the first core and fixed. At that time, the inner diameter side of the second yoke 44 is configured to be in contact with the second core or close to a slight clearance. Both the first yoke 42 and the second yoke 44 are made of magnetic stainless steel in order to form a magnetic circuit and in consideration of corrosion resistance, and the bobbin 45 and the connector 47 are made of high-strength heat-resistant resin in consideration of strength characteristics and heat resistance characteristics. .. For the coil 43, copper is used, and for the terminal 46, brass plated with metal is used.

By configuring the solenoid mechanism portion and the coil portion as described above, a magnetic circuit is formed by the first core 38, the first yoke 42, the second yoke 44, the second core 39, and the anchor 36, and a current is applied to the coil. When given, an electromagnetic force is generated between the second core 39 and the anchor 36, and a force attracted to each other is generated. In the first core 38, by making the axial portion where the second core 39 and the anchor 36 generate attractive forces to each other as thin as possible, almost all of the magnetic flux passes between the second core and the anchor, which is efficient. Electromagnetic force can be obtained well.

When the electromagnetic force exceeds f1, the anchor 36, which is a movable portion, is attracted to the second core 39 together with the rod 35, and the core 39 and the anchor 36 come into contact with each other to continue the contact.

≪Inhalation process≫
When the plunger 2 starts to descend from the top dead center, the pressure in the pressurizing chamber sharply decreases from a high pressure state of, for example, 20 MPa level, and the rod 35, the anchor 36, and the suction valve 30 are brought into contact with the suction valve by the above-mentioned force f1. Start moving in the valve opening direction of 30. When the suction valve 30 is opened, the fuel that has flowed into the inner diameter side of the valve seat 31 from the passage 31b of the suction valve seat begins to be sucked into the pressurizing chamber.

The suction valve 30 collides with the suction valve stopper 32, and the suction valve 30 stops at that position. Similarly, the rod 35 also stops at a position where the tip contacts the suction valve 30 (the valve opening position of the plunger rod). The anchor 36 also moves in the valve opening direction of the suction valve 30 at the same speed as the rod 35, but tries to continue moving by inertial force even after the rod 35 comes into contact with the suction valve 30 and stops. However, the anchor urging spring 41 overcomes the inertial force, the anchor 36 moves in the direction of approaching the second core 39 again, and the anchor 36 comes into contact with the rod brim portion 35a in a pressed manner (anchor valve opening). It can be stopped at (position). The state showing the positions of the anchor 36, the rod 35, and the suction valve 30 at this time is the state shown in FIG.

In the above description, the rod 35 and the anchor 36 are completely separated from each other, but the rod 35 and the anchor 36 may remain in contact with each other. In other words, the load acting on the contact portion between the rod brim portion 35a and the anchor 36 decreases after the rod stops moving, and when it reaches 0, the anchor 36 starts to separate from the rod, but it does not become 0 and a slight load. The setting force of the anchor urging spring 41 may be used.

When the suction valve 30 collides with the suction valve stopper 32, a problem of abnormal noise, which is an important characteristic of the product, occurs. The loudness of the abnormal noise is due to the magnitude of the energy at the time of the collision, but since the rod 35 and the anchor 36 are formed separately, the energy that collides with the suction valve stopper 32 is the energy of the suction valve 30. It will be generated only by the mass and the mass of the rod 35. That is, since the mass of the anchor 36 does not contribute to the collision energy, the problem of abnormal noise is reduced by forming the rod 35 and the anchor 36 separately.

Even if the rod 35 and the anchor 36 are separately configured, in the case where the anchor urging spring 41 is not provided, the anchor 36 continues to move in the valve opening direction of the suction valve 30 due to the inertial force, and the center of the rod guide 37. There arises a problem that the bearing portion 37a collides with the bearing portion 37a and an abnormal noise is generated at a portion different from the colliding portion. In addition to the problem of abnormal noise, the collision causes not only wear and deformation of the anchor 36 and the rod guide 37, but also metal foreign matter is generated due to the wear, and the foreign matter is caught between the sliding portion and the seat portion. In addition, the function of the suction valve solenoid mechanism may be impaired by being deformed and impairing the bearing function.

Further, in the case of the configuration without the anchor urging spring 41, the anchor is too far from the core 39 due to the inertial force, so that the current is applied to the coil portion in order to shift from the return process to the discharge process, which is a later process as the operation time. When the above is added, the problem that the required electromagnetic attraction cannot be obtained occurs.
If the required electromagnetic attraction cannot be obtained, there is a big problem that the fuel discharged from the high-pressure pump cannot be controlled to a desired flow rate. Therefore, the anchor urging spring 41 has an important function for not causing the above problem.

After the suction valve 30 is opened, the plunger 2 further descends to reach bottom dead center. During this time, fuel continues to flow into the pressurizing chamber 11, and this step is the suction step.

≪Return process≫
The plunger 2 that has descended to the bottom dead center enters the ascending process. The suction valve remains stopped in the valve open state by the force of f1, and the direction of the fluid passing through the suction valve is exactly opposite. That is, while the fuel flowed into the pressurizing chamber from the suction valve seat passage 31b in the suction step, it is returned from the pressurizing chamber in the direction of the suction valve seat passage 31b at the time of the ascending step. This process is called a return process.

In this return step, when the engine speed is high, that is, under the condition that the ascending speed of the plunger 2 is high, the valve closing force of the suction valve due to the returned fluid increases, and the force f1 decreases. Under this condition, if the setting force of each spring force is mistaken and f1 becomes a negative value, the suction valve 30 is unintentionally closed. Since a flow rate larger than the desired discharge flow rate is discharged, the pressure in the fuel pipe rises above the desired pressure, which adversely affects the combustion control of the engine. Therefore, it is necessary to set each spring force so that the force f1 maintains a positive value under the condition that the rising speed of the plunger 2 is the maximum.

≪Transition state from return process to discharge process≫
A current is applied to the electromagnetic coil 43 at an earlier time considering the delay in generating the electromagnetic force and the delay in closing the suction valve than the desired discharge time, and the magnetic attraction force acts between the anchor 36 and the second core 39. .. The current needs to give a current of a magnitude necessary to overcome the force f1. When the magnetic attraction force overcomes the force f1, the anchor 36 starts moving in the direction of the second core 39. As the anchor 36 moves, the rod 35 that is in contact with the brim 35a in the axial direction also moves, and the suction valve 30 moves the force and fluid force of the suction valve urging spring 33, mainly the pressurizing chamber. Valve closing is started by a decrease in static pressure due to the flow velocity passing through the seat from the side.

When a current is applied to the electromagnetic coil 43, if the anchor 36 and the second core 39 are too far apart from the specified distance, that is, if the anchor 36 continues to exceed the valve opening position, the magnetic attraction force is applied. Since it is weak, it cannot overcome the force f1, and it takes time for the anchor to move to the second core 39 side, or there is a problem that the anchor cannot move. An anchor urging spring 41 is provided so as not to cause this problem. When the anchor 36 cannot move to the second core 39 at a desired timing, the suction valve is maintained in an open state even at the desired discharge timing, so that the discharge process cannot be started, that is, the required discharge amount cannot be obtained, which is desired. There is a concern that the engine cannot be burned. Therefore, the anchor urging spring 41 has an important function for preventing the problem of abnormal noise that may occur in the suction process and for preventing the problem that the discharge process cannot be started.

The suction valve 30 that has started to move collides with the seat portion 31a and stops, so that the valve is closed. When the valve is closed, the in-cylinder pressure increases rapidly, so that the suction valve 30 is firmly pressed in the valve closing direction by the in-cylinder pressure with a force much larger than the force f1, and the valve closed state is started to be maintained.

The anchor 36 also collides with the second core 39 and stops. The rod 35 continues to move by inertial force even after the anchor 36 is stopped, but the rod urging spring 40 overcomes the inertial force and is pushed back, so that the brim portion 35a can return to the position where it contacts the anchor.

When the anchor 36 collides with the second core 39, the problem of abnormal noise, which is an important characteristic of the product, arises. This abnormal noise is larger than the loudness of the abnormal noise at which the suction valve and the suction valve stopper collide with each other, which is more problematic. The loudness of the abnormal noise is due to the magnitude of the energy at the time of the collision, but since the rod 35 and the anchor 36 are formed separately, the energy that collides with the second core 39 is the mass of the anchor 36. Will only occur. That is, since the mass of the rod 35 does not contribute to the collision energy, the problem of abnormal noise is reduced by forming the rod 35 and the anchor 36 separately.
Once the anchor 36 comes into contact with the second core 39, a sufficient magnetic attraction force is generated by the contact, so that the current value can be set to a small value only for maintaining the contact.

Here, the problem of erosion, which may occur in the solenoid mechanism, will be described. When an electric current is applied to the coil and the anchor 36 is attracted to the second core 39, the space volume between the two objects rapidly shrinks, causing the fluid in that space to lose its place and anchor with a fast flow. It is swept away to the outer peripheral side, collides with the thin part of the first core, and there is a concern that erosion will occur due to the energy. In addition, the swept fluid passes through the outer circumference of the anchor and flows to the rod guide side, but the flow velocity increases due to the narrow passage on the outer circumference side of the anchor, that is, cavitation occurs due to the rapid decrease in static pressure. There is a concern that cavitation erosion will occur in the thin part of one core.

In order to avoid these problems, one or more axial through holes 36a are provided on the center side of the anchor. This is because when the anchor 36 is attracted to the second core 39 side, the fluid in the space passes through the through hole 36a so as not to pass through the narrow passage on the outer peripheral side of the anchor as much as possible. With such a configuration, the above-mentioned problem of erosion can be solved.

When the anchor 36 and the rod 35 are integrally formed, an event occurs in which the above problem is further concerned. When the engine speed is high, that is, under the condition that the ascending speed of the plunger is high, the force applied to the coil to move the anchor 36 to the second core 39 and the force to close the suction valve 30 by the fluid having a very high speed are added. Increased as an additional force, the rod 35 and anchor 36 rapidly approach the second core 39, further increasing the speed at which the fluid in that space is pushed out, further exacerbating the erosion problem. If the capacity of the through hole 36a of the anchor 36 is insufficient, the problem of erosion cannot be solved.
In this embodiment, since the anchor 36 and the rod 35 are formed separately, even when the force for closing the suction valve 30 is applied to the rod 35, only the rod 35 is pushed out to the second core 39 side. While the anchor 36 is left behind, it moves to the second core 39 side with only a normal electromagnetic attraction force. That is, the space does not decrease suddenly, and the problem of erosion can be prevented.

As described above, the harmful effect of forming the anchor 36 and the rod 35 separately is that the desired magnetic attraction force cannot be obtained, abnormal noise, and functional deterioration. However, by installing the anchor urging spring 41, this harmful effect is obtained. Can be removed.

≪Discharge process≫
Immediately after the plunger shifts from the bottom dead center to the ascending process, the coil 43 is supplied with an electric current at a desired timing, and the return process until the suction valve 30 is closed is completed, the pressure in the pressurizing chamber rapidly increases, and the discharge process is performed. Become. After the discharge process, it is desirable to reduce the power applied to the coil from the viewpoint of power saving, so the current applied to the coil is cut off. No electromagnetic force is applied, and the anchor 36 and the rod 35 move in the direction away from the second core 39 due to the resultant force of the rod urging spring 40 and the anchor urging spring 41. However, since the suction valve 30 is in the valve closing position with a strong valve closing force, the rod 35 stops at the position where it collides with the suction valve 30 in the closed valve state. That is, the amount of movement of the rod at this time is (36e-30a).

The rod 35 and the anchor 36 move at the same time after the current is cut, but even after the tip of the rod 35 and the closed suction valve 30 stop in contact with each other, the anchor 36 still moves in the direction of the suction valve 30 due to inertial force. Try to continue moving to. However, since the anchor urging spring 41 overcomes the inertial force and gives the anchor 36 an urging force in the direction of the second core 39, the anchor 36 can be stopped in contact with the brim portion 35a of the rod 35.

When the anchor urging spring 41 is not provided, the anchor moves in the direction of the suction valve 30 without stopping, and there is a problem of abnormal noise and a problem of dysfunction that collides with the rod guide portion 31e, as described above for the suction process. Although there is concern, since the anchor urging spring 41 is installed, the above problem can be prevented. In this embodiment, the rod guide portion 31e is integrally formed of the same member as the suction valve seat member 31.

In this way, the discharge step of discharging the fuel is performed, and immediately before the next suction step, the suction valve 30, the rod 35, and the anchor 36 are in the state shown in FIG. When the plunger reaches top dead center, the discharge process is completed and the suction process is started again. Thus, the required amount of fuel guided to the low-pressure fuel suction port 10a is pressurized to a high pressure by the reciprocating movement of the plunger 2 in the pressurizing chamber 11 of the pump body 1 as the pump body, and the fuel is pressurized from the fuel discharge port 12 to the common rail 23. A high pressure pump suitable for pumping into a pump can be provided.
Here, in the electromagnetic suction valve of the conventional high-pressure fuel supply pump described in Patent Documents 1 and 2, the inclination becomes large when the suction valve and the rod collide with each other. When the suction valve and the rod collide with each other in an inclined state, the rods collide with each other in a corner contact state, so that there is a problem that stress concentration occurs and wear occurs.
Therefore, in the following, in the electromagnetic suction valve of the high-pressure fuel supply pump, a configuration for preventing wear at the rod collision portion by reducing the inclination of the suction valve and the rod will be described. In the high-pressure fuel supply pump of this embodiment, the suction valve 30 having the flat surface portion 30d, the rod portion 35 for urging the flat surface portion 30d in the valve opening direction, and the suction valve 30 formed at a position parallel to the flat surface portion 30d are provided. A seat member 31 having a seating suction valve seat 31a is provided, and the seat member 31 guides the rod portion 35 on the side opposite to the suction valve 30 with respect to the contact position between the rod portion 35 and the flat surface portion 30d. The guide portion 31d was formed.

Further, the flat surface portion 30d of the suction valve 30 and the suction valve seat 31a of the seat member 31 are formed on substantially the same flat surface. Further, the flat surface portion 30d of the suction valve 30 and the central axis of the rod portion 35 are arranged so as to be orthogonal to each other. Further, the seat member 31 is formed with a fuel passage 31b into which fuel from the low pressure flow path flows in, and a guide portion 31e is arranged on the side opposite to the suction valve seat 31a with respect to the opening of the fuel passage 31b. Further, the seat member 31 is formed with a fuel passage 31b into which fuel from the low pressure flow path flows in, and all of the guide portions 31e are arranged on the opposite side of the suction valve seat 31a with respect to the opening of the fuel passage 31b. .. Further, the seat member 31 is formed with a fuel passage 31b into which fuel from the low pressure flow path flows in, and the suction valve seat 31a is arranged on the side of the pressurizing chamber 11 with respect to the opening of the fuel passage 31a. Further, the seat member 31 is formed with a fuel passage 31b into which fuel from the low pressure flow path flows in, and all of the suction valve seats 31a are arranged on the pressurizing chamber 11 side with respect to the opening of the fuel passage 31b. ..

Further, a movable portion 36 that generates a magnetic attraction force is integrally attached to the rod portion 35, and a guide portion of the rod portion 35 is provided with respect to the length of the facing surface between the rod portion 35 and the movable portion 36 in the rod central axis direction. The seat member 31, the guide portion 31e, and the movable portion 36 are arranged so that the length of the 31e becomes long. A movable portion 36 that generates a magnetic attraction force is attached to the rod portion 35 separately, and the rod portion 35 and the movable portion 36 are in the rod central axis direction in a state where the rod portion 35 and the movable portion 36 are engaged with each other. The seat member 31, the guide portion 31e, and the movable portion 36 are arranged so that the length of the guide portion 31e of the rod portion 35 is longer than the length of the facing surface of the rod portion 35. The rod portion 35 and the suction valve 30 are made of separate members. The rod portion 35 and the suction valve 30 are made of separate members, and the length of the guide portion 31e in the direction of the rod center axis is more than half of the total length of the rod portion 35. And were configured.

With the above configuration, it is possible to prevent the rod from colliding in a tilted state, thereby preventing the rod from colliding in an angular contact state, and solving the problem of stress concentration and wear. ..

The low-pressure fuel chamber 10 is provided with a pressure pulsation reducing mechanism 9 that reduces and reduces the pressure pulsation generated in the high-pressure fuel supply pump from spreading to the fuel pipe 28. When the fuel that has once flowed into the pressurizing chamber 11 is returned to the suction passage 10d through the suction valve body 30 in the valve-opened state again for capacity control, the fuel returned to the suction passage 10d puts pressure on the low-pressure fuel chamber 10. Pulsation occurs. However, the pressure pulsation reduction mechanism 9 provided in the low pressure fuel chamber 10 is formed by a metal diaphragm damper in which two corrugated disk-shaped metal plates are bonded together on the outer periphery thereof and an inert gas such as argon is injected inside. The pressure pulsation is absorbed and reduced by the expansion and contraction of this metal damper.

The plunger 2 has a large diameter portion 2a and a small diameter portion 2b, and the volume of the sub chamber 7a increases or decreases due to the reciprocating motion of the plunger. The sub chamber 7a communicates with the low pressure fuel chamber 10 by the fuel passage 10e. When the plunger 2 is lowered, a fuel flow is generated from the sub chamber 7a to the low pressure fuel chamber 10, and when the plunger 2 is raised, a fuel flow is generated from the low pressure fuel chamber 10 to the sub chamber 7a.

This makes it possible to reduce the fuel flow rate inside and outside the pump during the suction stroke or the return stroke of the pump, and has a function of reducing the pressure pulsation generated inside the high-pressure fuel supply pump.

Next, the relief valve mechanism 200 shown in FIGS. 1 and 2 and the like will be described.
The relief valve mechanism 200 includes a relief body 201, a relief valve 202, a relief valve holder 203, a relief spring 204, and a spring stopper 205. The relief body 201 is provided with a tapered seat portion 201a. In the valve 202, the load of the relief spring 204 is applied via the valve holder 203, is pressed against the seat portion 201a, and shuts off the fuel in cooperation with the seat portion 201a. The valve opening pressure of the relief valve 202 is determined by the load of the relief spring 204. The spring stopper 205 is press-fitted and fixed to the relief body 201, and is a mechanism for adjusting the load of the relief spring 204 according to the press-fitting and fixing position.

Here, when the fuel in the pressurizing chamber 11 is pressurized and the discharge valve 8b is opened, the high-pressure fuel in the pressurizing chamber 11 passes through the discharge valve chamber 12a and the fuel discharge passage 12b and is transmitted from the fuel discharge port 12. It is discharged. The fuel discharge port 12 is formed in a discharge joint 60, and the discharge joint 60 is welded and fixed to the pump body 1 at a welded portion 61 to secure a fuel passage. Then, in this embodiment, the relief valve mechanism 200 is arranged in the space formed inside the discharge joint 60. That is, the outermost diameter portion of the relief valve mechanism 200 (in this embodiment, the outermost diameter portion of the relief body 201) is arranged on the inner peripheral side of the inner diameter portion of the discharge joint 60, and the pump body 1 is viewed from above. As seen, the relief valve mechanism 200 is arranged so as to overlap at least a part of the discharge joint 60 in the axial direction thereof.

It is desirable that the relief valve mechanism 200 is directly inserted into the hole formed in the pump body 1 and arranged in non-contact with the discharge joint 60. As a result, even if the shape of the discharge joint 60 changes, it is not necessary to change the shape of the relief valve mechanism 200 in response to this, and it is possible to reduce the cost.

That is, in this embodiment, as shown in FIG. 1, the first hole 1c (horizontal hole) is formed in the direction (lateral direction) orthogonal to the plunger axial direction from the outer peripheral surface of the pump body 1 toward the inner peripheral side. The relief valve mechanism 200 is arranged by pressing the relief body 201 into the first hole 1c (horizontal hole). Then, in this embodiment, when the relief valve mechanism 200 is opened by communicating with the first hole 1c (horizontal hole), the fuel in the discharge side flow path is supplied from the discharge valve 8b pressurized in the pressurizing chamber 11. A second hole 1d (vertical hole) to be returned to the damper chamber 10c was formed in the pump body 1.

Specifically, when the relief valve 202 is opened, the discharge side flow path (fuel discharge port 12) and the internal space of the relief body 201 communicate with each other. A relief valve holder 203, a relief spring 204, and a spring stopper 205 are arranged in this internal space. A hole is formed in the center of the spring stopper 205 when viewed in the direction of the relief valve axis, whereby the internal space of the relief body 201 and the relief passage 213 formed by the second hole 1d (vertical hole) are connected. The end of the relief body 201 on the side where the spring stopper 205 is arranged is an opening, and the relief valve 202, the relief valve holder 203, the relief spring 204, and the spring stopper 205 are inserted in this order from this opening. The relief valve mechanism 200 is configured.

The second hole (vertical hole) is formed from the outer circumference of the relief spring 204 toward the damper chamber 10c. Then, when the relief valve 202 is opened, the fuel in the internal space of the relief body 201 flows into the damper chamber 10c through the hole in the center of the spring stopper 205, the opening of the relief body 201, and the relief passage 213. ..

When the high-pressure fuel supply pump is operating normally, the fuel pressurized by the pressurizing chamber 11 passes through the fuel discharge passage 12b and is discharged at high pressure from the fuel discharge port 12. In this embodiment, the target fuel pressure of the common rail 23 is 35 MPa. The pressure in the common rail 23 repeats pulsation with time, but the average value is 35 MPa.

Immediately after the start of the pressurization stroke, the pressure in the pressurizing chamber 11 suddenly rises above the pressure in the common rail 23, and in this embodiment, the peak value rises to about 43 MPa, and the pressure in the fuel discharge port 12 also rises accordingly. It rises to about 41.5 MPa at the peak in this example. In this embodiment, the valve opening pressure of the relief valve mechanism 200 is set to 42 MPa at the peak, the pressure of the fuel discharge port 12 which is the inlet of the relief valve mechanism 200 is set not to exceed the valve opening pressure, and the relief valve mechanism 200 Does not open.

Next, the case where abnormally high pressure fuel is generated will be described.
When the pressure of the fuel discharge port 12 becomes abnormally high due to a failure of the electromagnetic suction valve 300 of the high-pressure fuel supply pump and becomes larger than the set pressure of 42 MPa of the relief valve mechanism 200, the abnormally high-pressure fuel is on the low-pressure side via the relief passage 213. It is relieved in the damper room 10c.

The advantage of having a configuration in which the abnormally high pressure fuel is relieved on the low pressure side (damper chamber 10c in this embodiment) will be described. It is possible to relieve abnormally high-pressure fuel generated due to a failure of the high-pressure fuel supply pump or the like in all the processes of the suction stroke, the return stroke, and the discharge stroke to a low pressure. On the other hand, if the abnormally high pressure fuel is relieved in the pressurizing chamber 11, the abnormally high pressure fuel can be relieved to the pressurizing chamber 11 only in the suction stroke and the returning stroke, and the abnormally high pressure fuel can be relieved in the pressurizing stroke. Can not. Since the outlet of the relief valve is the pressurizing chamber 11, the pressure in the pressurizing chamber 11 rises in the pressurizing stroke, and the differential pressure between the inlet and the outlet of the relief valve does not exceed the set pressure of the relief spring. As a result, the time for relieving the abnormally high-pressure fuel is shortened, and the relief function is deteriorated. In this embodiment, the relief is returned to the low pressure side.
In this embodiment, the relief valve mechanism 200 is externally assembled as a sub-assembly before being mounted on the pump body 1. After the assembled relief valve mechanism 200 is press-fitted and fixed to the pump body 1, the discharge joint 60 is welded and fixed to the pump body 1. Then, in this embodiment, as shown in FIG. 1, at least a part of the relief valve mechanism 200 arranged in the first hole 1c (horizontal hole) is added to the uppermost surface end portion 6b of the cylinder 6 on the pressurizing chamber side. It is configured to be arranged on the pressure chamber side (upper side in FIG. 1).

That is, when all of the relief valve mechanism 200 is located on the opposite side (lower side in FIG. 1) of the cylinder 6 with respect to the uppermost surface end portion 6b on the pressurizing chamber side, the relief valve mechanism 200 or the first The pump body 1 between the second hole 1d (vertical hole) and the cylinder 6 becomes thinner. When the relief valve mechanism 200 is opened, abnormally high pressure fuel flows into the internal space of the relief body 201 and the second hole 1d (vertical hole). Therefore, it is important from the viewpoint of reliability that the relief valve mechanism 200 or the pump body 1 between the second hole 1d (vertical hole) and the cylinder 6 is made thick to some extent. Conversely, if this is thin, the thickness between the pressurizing chamber and the pressurizing chamber will be thin, which will lead to a decrease in reliability when abnormally high pressure fuel flows.

Therefore, by arranging the relief valve mechanism 200 as in the present embodiment described above, it is possible to secure this thickness and improve the reliability. In order to secure the thickness of the relief valve mechanism 200 and the pressurizing chamber 11, as shown in FIG. 1, all of the relief valve mechanism 200 is above the uppermost end portion 6b of the cylinder 6 on the pressurizing chamber side. It is desirable to be located in.

Further, as shown in FIG. 1, the relief valve mechanism 200 arranged in the first hole 1c (horizontal hole) is on the cylinder side (FIG. 1) of the pressurizing chamber 11 on the opposite side (upper side in FIG. 1) of the uppermost end portion 11a. Then it is desirable to place it on the lower side). Specifically, it is desirable that the relief valve mechanism 200 is arranged between the uppermost end portion 11a of the pressurizing chamber 11 on the opposite side of the cylinder and the uppermost surface end portion 6b of the cylinder 6 on the pressurizing chamber side.

As a result, the relief valve mechanism 200 can be provided on the same plane as the discharge joint 60, the electromagnetic suction valve mechanism 300, and the discharge valve mechanism 8, and the workability can be improved in manufacturing the pump body 1. .. Specifically, the central axis of the relief valve mechanism 200, that is, the central axis of the relief body 201, the relief valve holder 203, or the spring stopper 205 is arranged substantially linearly with the central axis of the electromagnetic suction valve mechanism 300 (rod 35). Will be done. Therefore, the assembling property of the high-pressure fuel supply pump can be improved.

Further, as shown in FIG. 1, the position 1e in which the upper end portion of the first hole 1c (horizontal hole) is connected to the second hole 1d (vertical hole) is the pressurizing chamber with respect to the uppermost end portion 6b on the pressurizing chamber side of the cylinder 6. It is arranged on the side (upper side in FIG. 1). The position 1e at which the upper end of the first hole 1c (horizontal hole) is connected to the second hole 1d (vertical hole) is located below the uppermost end 11a on the opposite cylinder side of the pressurizing chamber 11. Is desirable. As a result, the thickness of the relief valve mechanism 200 or the pump body 1 between the second hole 1d (vertical hole) and the cylinder 6 can be secured, so that reliability can be ensured while reducing the size of the fuel supply pump. ..

In this embodiment, the second hole 1d (vertical hole) is formed downward from the opening 213a of the pump body 1 with respect to the first hole 1c (horizontal hole), and the first hole 1c is formed. The relief passage 213 can be easily formed only by communicating with the (horizontal hole). Further, since the discharge joint 60 is arranged so as to cover the first hole 1c (horizontal hole) and the relief valve mechanism 200 is arranged inside the discharge joint 60, the size of the pump body 1 and the high-pressure fuel supply pump can be increased. It can be avoided.

All of the relief passages 213 are formed on the inner peripheral side with respect to the outermost peripheral portion of the pressure pulsation reducing mechanism 9 when viewed from the axial direction of the plunger 2. This makes it possible to open the abnormally high pressure fuel to the low pressure passage 10c without increasing the size of the pump body 1. It is desirable that the diameter of the first hole 1c (horizontal hole) is larger than the diameter of the second hole 1d (vertical hole). Since the relief valve 200 is press-fitted to the first hole 1c (horizontal hole), the bottom surface of the first hole serves as a stopper for the relief valve 200.

In this embodiment, since the relief body 201 is provided, the diameter of the first hole 1c (horizontal hole) is the same as the outer diameter of the relief body. Further, it is desirable that the diameter of the passage formed in the spring stopper 205 on the downstream side of the relief valve 202 is smaller than that of the second hole 1d (vertical hole). The fuel released from the abnormally high pressure to the low pressure via the relief valve 200 has a large momentum. With such a configuration, this momentum can be reduced, and the pressure pulsation reduction mechanism 9 and other parts can be reduced. Can be prevented from being damaged.

The second hole 1d (vertical hole) forming the relief passage 213 opens to the damper chamber 10c in which the pressure pulsation reducing mechanism 9 for reducing the low pressure pulsation is housed by the opening 213a. Then, a holding member 9a for fixing and holding the pressure pulsation reducing mechanism 9 is arranged between the opening 213a and the pressure pulsation reducing mechanism 9. The abnormally high-pressure fuel is released through the relief passage 213, and at that time, the fuel released from the opening 213a flows into the low-pressure passage 10c at a high speed and collides with the holding member 9a. As a result, when the abnormally high pressure fuel is released to a low pressure, the problem that the pressure pulsation reducing mechanism 9 is damaged due to the large speed can be avoided.

The holding member 9a is formed with an elastic portion 9b that urges the pressure pulsation reducing mechanism 9 toward the damper cover 14 by urging a flat portion that is flush with the opening 213a of the pump body 1. Specifically, one metal plate of the holding member 9a is formed by press working, and at that time, a part of the bottom portion of the holding member 9a is cut up toward the flat surface portion on the side of the opening 213a of the pump body. As a result, an elastic portion is formed. Then, when the damper cover 14 is attached to the pump body 1, the convex portion of the damper cover 14 urges the pressure pulsation reduction mechanism 9 toward the pump body 1, whereby the cut-up 9b of the holding member 9a is flattened by the pump body 1. Equip the department.
The cut-up 9b of the holding member 9a urges a portion other than the opening 213a when the pump body 1 is viewed from above. As a result, the cut-up 9b of the holding member 9a and the pump body 1 can be ensured to come into contact with each other, so that the pressure pulsation reduction mechanism 9 can be stably supported.

1 Pump body 2 Plunger 6 Cylinder 7 Seal holder 8 Discharge valve mechanism 9 Pressure pulsation reduction mechanism 10a Low pressure fuel suction port 11 Pressurization chamber 12 Fuel discharge port 13 Plunger seal 30 Suction valve 40 Rod urging spring 43 Electromagnetic coil 100 Pressure pulsation propagation Prevention mechanism 101 Valve seat 102 Valve 103 Spring 104 Spring stopper 200 Relief valve 201 Relief body 202 Valve holder 203 Relief spring 204 Spring stopper 300 Electromagnetic suction valve mechanism

Claims (12)

A suction valve with a flat surface and
A rod portion that collides with the flat surface portion and urges the suction valve in the valve opening direction, and a rod portion.
A seat member having a surface parallel to the flat surface portion and having a suction valve seat on which the flat surface portion of the suction valve is seated is provided.
The suction valve seat is configured on the same flat surface as the collision surface on which the rod portion of the flat surface portion collides.
The seat member is provided with a fuel passage through which fuel flows from the low pressure flow path.
A guide portion that guides the rod portion on the side opposite to the suction valve with respect to the contact position between the rod portion and the flat surface portion is formed integrally with the seat member.
The guide portion provided with respect to the rod portion is provided at only one place and at a position not overlapping with the opening of the fuel passage.
The rod portion is the only member provided at a position overlapping the opening of the fuel passage.
A high-pressure fuel supply pump in which the thickness of the suction valve in the rod portion axial direction is thicker than the thickness of the portion of the seat member where the suction valve seat is provided in the rod portion axial direction. In the high-pressure fuel supply pump according to claim 1,
A high-pressure fuel supply pump arranged so that the flat surface portion of the suction valve and the central axis of the rod portion are orthogonal to each other. In the high-pressure fuel supply pump according to claim 1,
A fuel passage through which fuel from the low-pressure flow path flows is formed in the seat member, and a high-pressure fuel supply pump in which the guide portion is arranged on the side opposite to the suction valve seat with respect to the opening of the fuel passage. .. In the high-pressure fuel supply pump according to claim 1,
A fuel passage through which fuel flows from the low-pressure flow path is formed in the seat member, and all of the guide portions are arranged on the opposite side of the suction valve seat with respect to the opening of the fuel passage. Supply pump. In the high-pressure fuel supply pump according to claim 1,
A high-pressure fuel supply pump in which a fuel passage through which fuel from a low-pressure flow path flows is formed in the seat member, and the suction valve seat is arranged on the pressurizing chamber side with respect to the opening of the fuel passage. In the high-pressure fuel supply pump according to claim 1,
A fuel passage through which fuel flows from the low-pressure flow path is formed in the seat member, and a high-pressure fuel supply pump in which all of the suction valve seats are arranged on the pressurizing chamber side with respect to the opening of the fuel passage. .. In the high-pressure fuel supply pump according to claim 1,
A movable part that generates magnetic attraction is integrally attached to the rod part.
The seat member, the guide portion, and the movable portion so that the length of the guide portion of the rod portion is longer than the length of the facing surface between the rod portion and the movable portion in the rod central axis direction. Is located in a high pressure fuel supply pump. In the high-pressure fuel supply pump according to claim 1,
A high-pressure fuel supply pump in which a movable part that generates magnetic attraction is attached to the rod part separately. In the high-pressure fuel supply pump according to claim 8.
In the state where the rod portion and the movable portion are engaged, the length of the guide portion of the rod portion is longer than the length of the facing surface between the rod portion and the movable portion in the rod central axis direction. A high-pressure fuel supply pump in which the seat member, the guide portion, and the movable portion are arranged so as to be. In the high-pressure fuel supply pump according to claim 1,
A high-pressure fuel supply pump in which the rod portion and the suction valve are separate members. In the high-pressure fuel supply pump according to claim 1,
The rod portion and the suction valve are made of separate members, and the length of the guide portion is more than half of the total length of the rod portion in the direction of the rod center axis. A high-pressure fuel supply pump configured with and. In the high-pressure fuel supply pump according to claim 1,
Further, a suction valve stopper that is press-fitted and held inside the cylindrical seat member to regulate the movement of the suction valve is provided.
The suction valve stopper is a high-pressure fuel supply pump held inside the seat member with its outer peripheral surface in contact with the inner peripheral surface of the seat member.

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